An ancient nautilus shell may be easily identifiable, but other parts of the nautilus, from its soft tissue to its genome, have almost certainly changed in the same period. Those adaptations may be relatively small compared to, say, humans, who only emerged as a distinct species (Homo sapiens) in the last 300,000 years, but they can't be counted out entirely. “I think it's unlikely [the nautilus’s] ancestors had 90 tentacles,” Basil says by way of example. “I think that's an adaptation to moving to a dark place where being able to taste and smell is adaptive.” Basil adds that the nautilus appears to be changing even today, albeit not always in ways we humans immediately understand. “They're actually undergoing a period of rapid diversification right now,” she says.

Anthropocentrism could be clouding our appraisal of the nautilus—and perhaps other members of the animal kingdom—in more subtle ways, too. Basil has dedicated her life to studying the intelligence of the nautilus....